Submicron dimensional calibration standards and methods of manufacture and use

Abstract

A calibration standard which may be used to calibrate lateral dimensional measurement systems is provided. The calibration standard may include a first substrate spaced from a second substrate. In addition, the calibration standard may include at least one layer disposed between the first and second substrates. The layer may have a traceably measured thickness. For example, a thickness of the layer may be traceably measured using any measurement technique in which a measurement system may be calibrated with a standard reference material traceable to a national testing authority. The calibration standard may be cross-sectioned in a direction substantially perpendicular to an upper surface of the first substrate. The cross-sectioned portion of the calibration standard may form a viewing surface of the calibration standard. In this manner, a lateral dimensional artifact of the calibration standard may include the traceably measured thickness of at least the one layer.

What is claimed is:  
     
       1. A calibration standard, comprising: 
       a first substrate spaced from a second substrate; and  
       at least one layer disposed between the first and second substrates, wherein the at least one layer comprises a traceably measured thickness, wherein a viewing surface of the calibration standard comprises a cross-sectional surface of the calibration standard, and wherein the cross-sectional surface is substantially perpendicular to an upper surface of at least the first substrate such that a lateral dimensional artifact of the calibration standard comprises the traceably measured thickness of the at least one layer.  
     
     
       2. The standard of  claim 1 , wherein the traceably measured thickness comprises less than approximately 500 nm. 
     
     
       3. The standard of  claim 1 , wherein the traceably measured thickness is determined using a traceable measurement technique, and wherein the traceable measurement technique comprises thin film metrology. 
     
     
       4. The standard of  claim 1 , wherein the traceably measured thickness is determined using a traceable measurement technique, and wherein the traceable measurement technique comprises ellipsometry. 
     
     
       5. The standard of  claim 1 , wherein the traceably measured thickness is determined using a traceable measurement technique, and wherein the traceable measurement technique comprises spectrophotometry. 
     
     
       6. The standard of  claim 1 , wherein the traceably measured thickness is determined using a traceable measurement technique, and wherein the traceable measurement technique comprises interferometry. 
     
     
       7. The standard of  claim 1 , wherein the traceably measured thickness is determined using a traceable measurement technique, and wherein the traceable measurement technique comprises profilometry. 
     
     
       8. The standard of  claim 1 , wherein the traceably measured thickness is determined using a traceable measurement technique, and wherein the traceable measurement technique comprises cross-sectional TEM. 
     
     
       9. The standard of  claim 1 , wherein the traceably measured thickness is determined with a measurement system calibrated with a standard reference material traceable to a national testing authority. 
     
     
       10. The standard of  claim 1 , wherein the viewing surface is substantially planar. 
     
     
       11. The standard of  claim 1 , wherein the viewing surface is substantially non-planar. 
     
     
       12. The standard of  claim 1 , wherein a portion of the at least one layer extending from the cross-sectional surface is removed to form a trench in the calibration standard. 
     
     
       13. The standard of  claim 1 , wherein a portion of the first and second substrates extending from the cross-sectional surface is removed such that the at least one layer forms a topographic feature of the calibration standard, and wherein the topographic feature comprises a line. 
     
     
       14. The standard of  claim 1 , wherein the at least one layer is formed within a trench of the calibration standard, and wherein reentrant knife-edge structures are formed at upper comers of the trench. 
     
     
       15. The standard of  claim 1 , wherein the at least one layer comprises a material of a feature formed by a semiconductor fabrication process, and wherein a lateral dimension of the feature is to be measured with a lateral dimensional measurement system calibrated with the calibration standard. 
     
     
       16. The standard of  claim 1 , wherein the traceably measured thickness is approximately equal to a lateral dimension of a feature formed by a semiconductor fabrication process, and wherein the lateral dimension of the feature is to be measured with a lateral dimensional measurement system calibrated with the calibration standard. 
     
     
       17. The standard of  claim 1 , further comprising at least three layers disposed between the first and second substrates, wherein the at least three layers comprise at least one feature of the calibration standard. 
     
     
       18. The standard of  claim 1 , further comprising at least three layers disposed between the first and second substrates, wherein the at least three layers comprise at least a first feature and a second feature, and wherein a traceably measured thickness of the first feature is approximately equal to a traceably measured thickness of the second feature. 
     
     
       19. The standard of  claim 1 , further comprising at least three layers disposed between the first and second substrates, wherein the at least three layers comprise at least a first feature and a second feature, and wherein a traceably measured thickness of the first feature is substantially different than a traceably measured thickness of the second feature. 
     
     
       20. The standard of  claim 1 , wherein the first substrate or the second substrate comprises a semiconductor. 
     
     
       21. The standard of  claim 1 , wherein the first substrate or the second substrate comprises quartz. 
     
     
       22. The standard of  claim 1 , wherein the first substrate or the second substrate comprises glass. 
     
     
       23. A method for forming a calibration standard, comprising: 
       forming at least one layer upon an upper surface of a first substrate;  
       determining a thickness of the at least one layer using a traceable measurement technique;  
       bonding a second substrate to an upper surface of the at least one layer; and  
       cross-sectioning the first substrate, the at least one layer, and the second substrate in a plane substantially perpendicular to at least the upper surface of the first substrate to form a viewing surface of the calibration standard such that a lateral dimensional artifact of the calibration standard comprises the determined thickness of the at least one layer.  
     
     
       24. The method of  claim 23 , wherein the determined thickness comprises less than approximately 500 nm. 
     
     
       25. The method of  claim 23 , wherein the traceable measurement technique comprises thin film metrology. 
     
     
       26. The method of  claim 23 , wherein the traceable measurement technique comprises ellipsometry. 
     
     
       27. The method of  claim 23 , wherein the traceable measurement technique comprises spectrophotometry. 
     
     
       28. The method of  claim 23 , wherein the traceable measurement technique comprises interferometry. 
     
     
       29. The method of  claim 23 , wherein the traceable measurement technique comprises profilometry. 
     
     
       30. The method of  claim 23 , wherein the traceable measurement technique comprises cross-sectional TEM. 
     
     
       31. The method of  claim 23 , wherein determining the thickness of the at least one layer comprises calibrating a measurement system with a standard reference material traceable to a national testing authority. 
     
     
       32. The method of  claim 23 , further comprising planarizing the cross-sectioned first substrate, the at least one layer, and second substrate such that the viewing surface is substantially planar. 
     
     
       33. The method of  claim 23 , further comprising removing a portion of the first substrate, the at least one layer, and the second substrate extending from the viewing surface such that the viewing surface is substantially non-planar. 
     
     
       34. The method of  claim 23 , further comprising removing a portion of the first and second substrates extending from the viewing surface such that the at least one layer forms a topographic feature of the calibration standard, and wherein the topographic feature comprises a line. 
     
     
       35. The method of  claim 23 , further comprising removing a portion of the at least one layer extending from the viewing surface to form a trench in the calibration standard. 
     
     
       36. The method of  claim 23 , further comprising forming a thermally grown oxide on upper surfaces of the first and second substrates and on sidewall surfaces of a trench formed in the calibration standard. 
     
     
       37. The method of  claim 36 , further comprising removing the thermally grown oxide to form reentrant knife-edge structures at upper comers of the trench. 
     
     
       38. The method of  claim 36 , further comprising depositing a material on the thermally grown oxide and planarizing the deposited material and the thermally grown oxide such that upper surfaces of the thermally grown oxide and the deposited material are substantially planar with upper surfaces of the first and second substrates. 
     
     
       39. The method of  claim 38 , further comprising determining a thickness of at least the thermally grown oxide or the deposited material using a traceable measurement technique. 
     
     
       40. The method of  claim 38 , further comprising removing a portion of the thermally grown oxide to form trenches in the calibration standard. 
     
     
       41. The method of  claim 23 , wherein the at least one layer comprises a material of a feature formed by a semiconductor fabrication process, and wherein a lateral dimension of the feature is to be measured with a lateral dimensional measurement system calibrated with the calibration standard. 
     
     
       42. The method of  claim 23 , wherein the determined thickness of the at least one layer comprises approximately a lateral dimension of a feature formed by a semiconductor fabrication process, and wherein the lateral dimension of the feature is to be measured with a lateral dimensional measurement system calibrated with the calibration standard. 
     
     
       43. The method of  claim 23 , wherein the at least one layer comprises at least three layers, and wherein the at least three layers comprise at least one feature of the calibration standard. 
     
     
       44. The method of  claim 23 , wherein the at least one layer comprises at least three layers, wherein the at least three layers form at least a first feature and a second feature of the calibration standard, and wherein a determined thickness of the first feature is approximately equal to a determined thickness of the second feature. 
     
     
       45. The method of  claim 23 , wherein the at least one layer comprises at least three layers, wherein the at least three layers form at least a first feature and a second feature of the calibration standard, and wherein a determined thickness of the first feature is substantially different than a determined thickness of the second feature. 
     
     
       46. The method of  claim 23 , wherein the first substrate or the second substrate comprises a semiconductor. 
     
     
       47. The method of  claim 23 , wherein the first substrate or the second substrate comprises quartz. 
     
     
       48. The method of  claim 23 , wherein the first substrate or the second substrate comprises glass. 
     
     
       49. A method for calibrating a lateral dimensional measurement system, comprising: 
       determining a thickness of at least one layer of a calibration standard with the system, wherein the calibration standard comprises:  
       a first substrate spaced from a second substrate; and  
       at least one layer disposed between the first and second substrates, wherein the at least one layer comprises a traceably measured thickness, wherein a viewing surface of the calibration standard comprises a cross-sectional surface of the calibration standard, and wherein the cross-sectional surface is substantially perpendicular to an upper surface of at least the first substrate such that a lateral dimensional artifact of the calibration standard comprises the traceably measured thickness of the at least one layer; and  
       altering calibration factors of the measurement system if the determined lateral dimension is not substantially equal to the lateral dimensional artifact of the calibration standard.